Why India is selected as standard Meridian

What is the difference between external & internal migration

In a world that produces enough food for every human, why is the distribution of food consumption and production so unequal? in a few sentences, explain why production and consumption of food is lower in the least-development countries (ldcs).

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite